Protagonists[edit]
These are the good guys. It includes all four of the main characters. In story mode, you can only control Aiai, but in Challenge, Practice, and Party Modes you can play as any of them.
Aiai[edit]
"The hero of this game. He loves bananas so much that he always spends his carefree life thinking: 'The banana I had today was really delicious.' Eat bananas and he'll be in high spirits, able to overcome any hardship. Chanting a magical spell 'Ei-Ei-Poo,' he starts his adventure with Monkey Ball," from the Super Monkey Ball 2 Instruction Booklet.
Meemee[edit]
"She is the future bride of Aiai. Unlike carefree Aiai, she is a person...umm...monkey with firm character. Although she loves Aiai more than anything else in the world, it seems that Aiai loves bananas more than her. And that makes her a little discontent. A little bit tomboyish, she is very kind to everyone on Jungle Island. She decorates herself with flowers that have a nice scent," from the Super Monkey Ball 2 Instruction Booklet.
Baby[edit]
'He came from the future to stop Dr. Bad-Boon's plot to prevent the marriage between Aiai and Meemee. He is in fact the son of Aiai and Meemee. He rarely cries, but once he does, he cries with the loudest voice on Jungle Island. Only Meemee can stop his crying," from the Super Monkey Ball 2 Instruction Booklet.
Gongon[edit]
"Yesterday's enemy is today's friend. He used to be Aiai's rival, but now they are best friends. He is quite rowdy, but places such a great value on friendship that once he becomes a friend he never betrays. Although he is still not big in size, he has great strength, and he trains himself every day to become the strongest monkey in the world," from the Super Monkey Ball 2 Instruction Manual.
Antagonists[edit]
This is the bad guys. It includes Dr. Bad-Boon and his assistant.